Here is the full list of all 50 Tomb Raider achievements. It takes around 40-50 hours to unlock all of the achievements on Windows.
Buy every upgrade and character in multiplayer.
Reach level 60 in multiplayer.
Purchase a new multiplayer character.
Find all documents, relics and GPS caches.
Fully mod and completely upgrade all weapons.
Complete all challenges.
Complete all optional tombs.
Purchase all skills in all categories.
Find 75% of GPS caches.
Collect 75% of all relics.
Fully mod and completely upgrade any weapon.
Find 75% of all documents.
Kill and loot 10 flying animals (crows and gulls).
Purchase all skills in one category.
Complete the game.
Complete all conversations with the Endurance crew.
Loot 200 enemies.
Incapacitate 25 enemies with dodge counter.
Rope pull 5 enemies off edges.
Collect 25% of all relics.
Kill FeeFee the crab.
Kill 50 enemies with the bow.
Kill 35 enemies with the pistol.
Kill 40 enemies with the shotgun.
Kill 25 unaware enemies.
Kill 75 enemies with the rifle.
Collect 5000 pieces of salvage.
Shoot 10 enemies off zip lines.
Find 25% of GPS caches.
Force an enemy to drop dynamite that kills two people when exploding.
Shoot a bundle of dynamite out of the air.
Perform 50 headshot kills in the single player campaign.
Kill and loot 10 small animals (rabbits, chickens, rats).
Find 25% of all documents.
Perform 15 finishers.
Complete one challenge.
Kill and loot 10 large animals (deer, boar, wolves).
Complete one optional tomb.
Win a ranked match in every multiplayer mode.
Complete a match in all multiplayer modes.
Reach level 10 in multiplayer.
Survive 10 explosions in multiplayer.
Kill 20 enemy players in multiplayer using a turret.
Kill a zip-lining enemy player in multiplayer.
In multiplayer, escape death 3 times by using the rope ascender.
Kill 10 multiplayer enemies using your melee attack.
Catch a player in a snare trap in multiplayer.
Kill 2 multiplayer enemies with a single explosive.
Revive a teammate in a multiplayer match.
In multiplayer, be the only player on your team that isn't dead or downed.